Abstract 2939: Automation meets reliability: Use of Oncomine࣪precision assay on the Genexus࣪system for accurate identification of cancer biomarkers in FFPE and liquid biopsy samples
Authors: Thilanka Jayaweera, Nicholas Siepert, Brian Hradecky, Emilia Ostrowska, Iris Casuga, kristy Lea, Priyanka Kshatriya, Jian Gu, Jeff Schageman, Ru Cao, Angie Cheng, Kelli Bramlett
Journal: Cancer Research (2022)

Abstract Accurate and early detection of oncogenic markers may one day be the key to fighting cancer. However, with complex workflows, long turnaround times, and numerous user touch points of most sequencing platforms does not make the process attainable. In contrast, the fully automated Genexus࣪ system provides a specimen-to-report workflow for cancer research with minimal user touchpoints and single day turnaround time. FFPE (formalin-fixed paraffin embedded) tissues and liquid biopsy are two of the main sample types used in oncology research. Here we report the use of the Oncomine࣪ Precision Assay (OPA) with the Genexus࣪ System which provides a comprehensive genetic profile across 50 key genes using DNA and RNA from FFPE tissues or cfTNA (cell free total nucleic acid) from liquid biopsy samples. To evaluate the nucleic acid (NA) extraction and sequencing performance of the Genexus࣪ system, contrived control samples with known variants and clinical research samples were used in the OPA FFPE and liquid biopsy workflows (n = 30). NA was quantified using the Genexus࣪ purification instrument’s onboard Qubit࣪ quantitation feature after purification. Output plates with extracted NA were transferred to the Genexus࣪ Integrated Sequencer for library preparation and sequencing using the OPA assay. Data were analyzed using the Ion torrent Genexus࣪ software to evaluate assay performance and variant calling.The OPA assay only requires 10ng of DNA and RNA from FFPE samples and 20ng of cfTNA from liquid biopsy samples. Genexus࣪ purification instrument onboard quantitation data showed successful extraction of NA exceeding the required yields for library preparation. Excess NA was automatically aliquoted into an archive plate and stored for future use. Sequencing results for four samples of FFPE or liquid biopsy were reported within 24 hours. Both Control and clinical research samples showed expected assay metrices including read coverage, molecular coverage, and uniformity. The results reported all expected variants at correct allele frequencies, including BRAF V600E, KRAS G12C, PIK3CA N345K, AKT1 etc. Overall, this study demonstrates that the Genexus࣪ system provides a user-friendly workflow with automated NA purification, quantitation, sample dilution, library preparation, sequencing, and data analysis with minimal hands-on time that can be performed with limited expertise to obtain results within 24 hours. Reliable identification of variants from control and clinical research samples of FFPE and liquid biopsy origin with optimal assay metrics demonstrates the successful use of the OPA assay and Genexus࣪ system that can be confidently used in clinical oncology research.(For Research Use Only. Not for use in diagnostic procedures.) Citation Format: Thilanka Jayaweera, Nicholas Siepert, Brian Hradecky, Emilia Ostrowska, Iris Casuga, kristy Lea, Priyanka Kshatriya, Jian Gu, Jeff Schageman, Ru Cao, Angie Cheng, Kelli Bramlett. Automation meets reliability: Use of Oncomine࣪precision assay on the Genexus࣪system for accurate identification of cancer biomarkers in FFPE and liquid biopsy samples [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2939.